The present invention relates to polycarbonate/ABS blends containing phosphonate amines and inorganic nanoparticles, which have improved flame-proofing and improved mechanical properties such as low-temperature notched impact strength, good elongation at break, weld line strength and stress cracking resistance as well as an improved yellowness index.
U.S. Pat. No. 4,073,767 and U.S. Pat. No. 5,844,028 describe cyclic phosphorus compounds which include phosphorinane rings as suitable flame retardants for polyurethanes, polyesters, polycarbonates and polyamides. U.S. Pat. No. 4,397,750 describes certain cyclic phosphonate esters as efficient flame retardants for polypropylene and other polyolefins. U.S. Pat. No. 5,276,066 and U.S. Pat. No. 5,844,028 describe certain (1,3,2-dioxaphosphorinanemethan)amines which are suitable flame retardants for polyurethanes, polyesters, styrene polymers, polyvinyl chloride, polyvinyl acetate and polycarbonate.
U.S. Pat. No. 3,505,431, FR-P 1 371 139, U.S. Pat. No. 3,711,577, U.S. Pat. No. 4,054,544 describe acyclic triphosphonate amines some of which are halogenated.
EP-A 0 640 655 describes moulding compositions prepared from aromatic polycarbonate, styrene-containing copolymers and graft polymers, which can be equipped to be flame-resistant with monomeric and/or oligomeric phosphorus compounds.
EP-A 0 363 608 describes as flame-proofing additives flame-resistant polymer mixtures prepared from aromatic polycarbonate, styrene-containing copolymer or graft copolymer as well as oligomeric phosphates. The heat deflection temperature of the latter mixtures is frequently insufficient for some applications such as, for example, mouldings within housing components.
U.S. Pat. No. 5,061,745 describes as flame-proofing additives polymer mixtures prepared from aromatic polycarbonate, ABS graft polymer and/or styrene-containing copolymer and monophosphates. The level of stress cracking resistance of the latter mixtures is frequently insufficient for producing thin-walled housing components.
The object of the present invention is to provide polycarbonate/ABS blends having a high heat deflection temperature, which have improved fire resistance and improved mechanical properties such as low-temperature strength, elongation at break, weld line strength and stress cracking resistance as well as an improved yellowness index. This combination of properties is a requirement particularly for applications in the information technology sector, such as for instance for housings of monitors, 2 printers or copiers.